


The Fourth Day of Gyftmas - Mistletoe

by MageOfLight



Series: 12 Days of Gyftmas - 2017 [5]
Category: Undertale
Genre: Begging, Face-Fucking, Sub Heat, Toys, but i'm out of time, double penitration, i should be adding more tags, so i'll fix this later
Language: English
Status: Completed
Published: 2017-12-16
Updated: 2017-12-16
Packaged: 2019-02-15 16:11:20
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,286
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13034730
Author URL: https://archiveofourown.org/users/MageOfLight/pseuds/MageOfLight
Summary: Sans goes into a sub heat. Red and Blue help.





	The Fourth Day of Gyftmas - Mistletoe

**Author's Note:**

  * For [Magyka13](https://archiveofourown.org/users/Magyka13/gifts).



> i don't feel entirely satisfied with this one because i'm in a rush to make sure it actually gets posted today. sorry it's not my best, Occulttale. orz

This was stupid. Sans hated parties, and yet here he was, at a big Gyftmas bash. Granted, it was mostly just his and Pap's alternates, and he hadn't wanted to disappoint Papyrus, who'd been so excited about this, but still...  
  
Sans was cranky, hot, and all he wanted was to leave. Still he bit all that back and forced a smile for everyone, studiously avoiding all laughing attempts by others (especially Red and Blue!) to get him under the mistletoe with them. Hell, avoiding contact with anyone else in the first place. He'd somehow avoided Blue's enthusiastic hugs for everyone who showed up without even offending the excitable swap Sans, and had managed to avoid it so far as well.  
  
Sighing, he ducked away from the group, finding a quiet out of the way nook of the swapbro's house to hide away in until the party ended. Papyrus would come looking for him when it was time to go, and then he could go home and hole away in his room for the next three days and take care of the mounting problem that was making him so hot and cranky in the first place.  
  
The small skeleton jerked awake an undetermined amount of time later to the sounds of quiet scolding and even more quiet snickering. "Red, stop! Sans was avoiding us all evening because of this!" Blue hissed from somewhere near by.  
  
"yeah? and? look ya can smell him same as me. he's not gonna be able ta take care of that on his own, anyway," Red returned from somewhere above him, snickering a little still, though his tone had turned more serious.  
  
"Yeah, but do you really need to play a prank on him like this?" Blue asked, and Sans' muzzily wondered what they were going on about, simply resting there and listening as Red snorted, finished what he was doing, then climbed off whatever he was standing on.  
  
"trust me, when he's more himself, he'll appreciate this joke. now ta wa-..." Red paused, likely noticing Sans' open sockets. "huh. sans? hey there, when'd ya wake up?" he asked, and Sans slowly looked up at him with hazy eyelights. "...holy fuck, blue, get over here. now," the taller hissed, prank apparently forgotten in the wake of whatever Red had seen.  
  
"What is it?" Blue asked, approaching cautiously and hovering over Sans and Red.  
  
"sans, sweetheart, look at blue, okay?" Red asked gently, and Sans blinked but did as told, craning his head up to meet Blue's gaze.  
  
"...oh..." Blue whispered. "Sans... how long have you been clamping down on your heat?" he asked sounding dismayed.  
  
"...mn...? ah... three days..." Sans replied slowly, barely understanding. Some distant part of him was alarmed about how slow and muzzy he felt, but it was buried under layers of heat and _want_. He wanted the two skeletons above him so bad it was a near physical ache. Pulses of heavy alarm from the other two souls tamped down on the urge to whine and reach for them, so he continued to lay there, slumped against the wall and waiting for something, _anything_ to happen.  
  
"how?!" Red demanded. Sans made a soft questioning sound and Red growled in frustration. "how the fuck did ya suppress yer heat for three whole fucking days?!"  
  
"oh... uh... suppressant serum... s'not hard... just gotta ween myself off... it..." That distant alarm suddenly became a lot more pressing as he spoke, and the muzzy haze cleared slightly in the sudden realization. "...fuck... i forgot a dose..."  
  
"oh, my fucking stars... yer supposed ta be the _smart one_ , sans! yer gonna explain why ya did that later, but for now... while yer a little more coherent... do we have yer consent ta help ya out?" Red growled.  
  
Sans looked between the two of them with widened sockets, a spike of worry helping keep his head clear. "but... the party..."  
  
"Everyone else went home, Sans. Red wanted to play a prank on you with the mistletoe, so we got Papy to take Papyrus home and get him settled into bed for you. He's supposed to stay there until you show up," Blue replied, and Sans blinked.  
  
...they were alone? Sans felt his resistance crumbling at that knowledge, the muzzy haze creeping back in. "...please... help me..." he murmured softly. Red didn't hesitate to take charge at that.  
  
"blue, get undressed," Red ordered, and Blue stared in surprise for a moment before hastening to comply, Sans watching with rapt attention at each piece of clothing that came off the smallest of the three of them. The sound of shifting leather drew his hazy eyelights back to Red, noting the largest of them shedding his jacket and tossing it carelessly aside before reaching for Sans. "common, sweetheart, let's get some of this stuff off ya," he murmured, and Sans fought to assist Red in getting his own jacket and sweater off. His soul pulsed unsteadily in his chest, casting a soft, pale blue light in the little nook they were sequestered away in and Sans couldn't help thinking that Red looked rather pretty bathed in his colour like that.  
  
The thought was instantly wiped from his mind when Red leaned forward and licked his sternum, tongue trailing along the faint scar left from a wound that didn't happen in the current timeline. The scar was exceptionally sensitive, and Sans arched into the wet touch, moaning loudly. "Oh..." Blue's voice seemed a million miles away as Red continued to lap at him, distracting him from noticing someone pulling down his shorts. Well, at least until a second tongue laved against his pelvis, anyway. Sans nearly screamed as a pussy snapped into sudden existence, nearly painfully quick and already soaked with his arousal.  
  
"fuck, he's pretty deep into his heat," Red growled, pulling away in order to speak to Blue. Sans slumped against the wall, panting heavily and making tiny, desperate sounds as hands skated over his ribs and a small hand wrapped around his spine, massaging the sensitive column of bone with surprising dexterity. When another hand brushed against his clit, that was all it took to push Sans over the edge into a very unsatisfying orgasm.  
  
"Stars, that..." Blue muttered, trying to ease Sans through it as he panted and whined in over stimulation.  
  
"yeah, this isn't gonna be easy on him at all," Red replied, then leaned in to kiss Sans, bringing him back a little. Sans' unfortunately low stamina was going to be an issue here, that much was clear. They just needed to figure out the best way to work him through it as smoothly as possible. "we should go slow. cumming that fast repeatedly is only gonna exhaust him without really helping with his heat... blue, can ya go get yer toy box?" Red asked, grinning.  
  
Blue flushed, knowing _exactly_ what toy box Red was talking about. But despite being embarrassed over even having them, he nodded and stood, going to retrieve them. He returned a few minutes later with a pile of blankets as well as a large towel, his toy box balanced neatly at the top of the pile. Wordlessly, the smallest Sans laid out the blankets, piling them on top of each other until there was a nice padded spot on the floor. "I knew all these old blankets would come in handy!" he chirped after he'd set up the makeshift bed. Red smirked back at him, lifting Sans and laying him out on the mass of blankets. Sans moaned at the contact, clinging to Red's sweater when Red tried to release him.  
  
"...please..." he whimpered.  
  
"don'cha worry, sweetheart. blue and i have got'cha. we're not gonna let ya suffer," Red reassured, and that was enough, barely, for Sans to release his sweater, allowing Red to dig into the toy box that Blue had dropped at his side. He was actually surprised to find each toy unpackaged and meticulously organized inside the box, having figured that Blue wouldn't have actually used such lewd items after bemoaning the gifts whenever Red or one of the fell-verse monsters decided to spring them on him as a gag gift. there was also a large, half-empty packet of batteries that had Red arching a brow in amused interest.  
  
"Not a word, Red. They... help with my heats. It feels better when I build myself up first before allowing myself to cum. That's exactly what you wanted them for here, isn't it?" Blue asked, and Red canted his head, surprised, though he knew he probably shouldn't be. Blue did like to be efficient in everything he did... and why _not_ use such tools when he was given them?  
  
"well, at least i know that the vibrators will have working batteries, anyway..." he replied with a soft laugh as Blue flushed a bit brighter. Sans whined, reaching out to tug at Red's pant leg as if to remind him that he was there, and Red chuckled. "i know, doll. we're gonna help ya," he said, patting the softer monster's hand.  
  
Blue dove into the box himself, pulling out a tin that was tucked in the corner and a container filled to the brim with what looked like small, wireless bullet vibes. Catching Red's questioning look, Blue's mouth twitched into a smirk that looked surprisingly good on him. "Razz told me about this little trick, and I've been itching to try it on someone, actually. It sadly doesn't work so well when doing it to yourself," he said, then popped open the tin.  
  
Inside were a number of baggies of what looked like gel slime. The smallest skeleton pulled one out and dumped the slime into his hand, playing with the cool cyan substance until it was oozing smoothly between his phalanges. Once that was done, he pressed the slime to Sans's ribcage, one hand delving inside to smooth the substance over itself, sealing it in place. Once that was done, he fished three of the bullets from the bag and imbedded the objects into the slime. "Watch this," he purred before his eyes lit up with magic. The three objects began glowing, then Sans arched, crying out at seemingly nothing. However, on closer inspection, the bullets seemed to be vibrating.  
  
"oh. oh man, that's clever. have to give props to that little fucker for this," Red growled, fighting back the mindless urge to fuck Sans into the floor as the incessant stimulation caused the scent of his heat to build in the room. Normally he had better control of himself, but Sans had gone into a deep sub heat, likely as a direct result of forcefully suppressing his heat. It was intensely hard to resist the siren song of Sans' need, and Blue looked like he was struggling just as hard, palming at his cock with one hand while massaging another handful of slime. "hey, blue. i'm well aware ya have stamina fer days. want me ta help take the edge off that fer ya while ya get more of those slime patches on him?" Red asked, and Blue let out a little moan at the offer, pulling his hand away from himself.  
  
Sans watched with rapt attention, despite how hazy and out of it with need he was, as Red moved behind Blue, bracing the smallest of them against his chest with one hand as the other reached around and firmly grasped his dick, pumping it slowly as he watched over Blue's shoulder. Sans was drooling now, and he seemed completely unaware of anything but Red's hand stroking Blue leisurely. Sans suddenly lurching up and crawling closer startled both of them, Red figuring he was already so far gone that any coordinated effort to move would have been near impossible.  
  
"...heh... never underestimate a sans, i guess..." Red muttered in awe as he was forced to remove his hand to avoid it being in the way as Sans went down on Blue, needily swallowing down the girthy cyan shaft. "shit, he's taking that so well..." the tallest breathed, watching as Sans began clumsily bobbing his head, licking and sucking at Blue to the point where the smallest skeleton was completely distracted from his task, moaning and thrusting into Sans' mouth desperately.  
  
Red swallowed heavily, then took the warmed slime from Blue before pressing it to Sans' sacrum and tail bone. He carefully massaged the slime into the holes and smoothed it into the grooves of his tail bone before reaching for a couple of the magic conductors. Red shot a look at Blue, who somehow managed to focus enough to catch it and nod at Red's silent askance. Red shot him a devilish grin in return, then pressed the two conductors into the slime, working the substance over the objects. As soon as he was done, a flash of magic set the conductors to vibrating just as Blue thrust hard into Sans' conjured throat.  
  
Sans' scream this time was muffled by Blue's cock buried to the root in his mouth, and Blue moaned, seizing up and cumming into Sans' throat. Red swallowed heavily himself at seeing Blue cum through the translucent magic of Sans' throat. "oh fuck, that's hot..." he muttered, resisting touching himself to the image, but only barely. Blue had the stamina to cum multiple times, but Red did not so he wanted to save that for being buried deep in Sans' cunt or ass. He didn't care which at that point, his magic throbbing with need that he ignored for now as he dug through the box until he pulled out a few toys he was satisfied with, as well as a large, half-empty bottle of lube. "gonna start prepping him," Red growled, and Blue nodded, a tiny whimper of overstimulation escaping him as Sans continued sucking and moaning around his still rock-hard cock.  
  
Red groaned at the sight, then turned away from it, trying not to pay any mind to the needy, desperate sounds Sans was making. He needed to focus on his task while Sans was distracted. Humming quietly to help himself focus, he picked up a thin glass wand and coated it heavily with lube. While Sans' cunt was slicked heavily with arousal and twitching around nothing, the ass he'd summoned along with it had no such advantage. Thus, all Red could do was carefully work the lubed up toy into him, listening to Sans' stifled moans and whimpers as the bumpy, ridged wand was worked into him.  
  
Red used that one for a bit, repeatedly pulling it out and reapplying the lube until Sans' ass was just as sloppy with lubrication as his pussy. He then switched to an inflatable dildo. At normal size, the toy was thin and rather unimposing, but he had one of these himself, Boss preferring to use it to prepare him for his massive cock whenever he went into a dominant heat and Red decided that he was going to refuse to form a cunt for him. He knew exactly how this felt when it started inflating, and he honestly couldn't wait to see Sans' reaction.  
  
Smirking, he lubed the toy and carefully pressed it in, Sans moaning at the feel of it stretching him further. Red didn't press it all the way in, though. It was designed to inflate inside, but wouldn't stretch Sans' entrance, which is what was needed. Slowly, he started to thrust it in and out, making Sans squirm around until he could easily cant his hips back into the toy, meeting Red's thrusts while still taking Blue's dick in his mouth, moaning desperately around him. Smirking, Red took the pump in his free hand, squeezing it once. Sans' mouth popped off of Blue's dick, his back arching with a sharp gasp. "fuck, fuck please, oh stars," Sans babbled and Red growled lowly.  
  
"blue, shut him up. i'm gonna burst if he keeps begging like that," he snarled, and Blue jumped to obey, guiding Sans back down to his cock without a word and thrusting back in. Sans didn't fight it, willingly taking Blue back into his mouth. This time, though, he kept his hands on Sans' skull to keep him from pulling off again. Red aimed a sharp smile at Blue in response, then continued thrusting the toy in and out, inflating it every minute or two until Sans was screaming desperately around Blue. Red had more than an idea or two of what Sans was trying to say, but he ignored him as best he could, finally lodging the toy entirely in Sans' ass before inflating it three more times in quick succession to make sure it stayed put. The process had Sans tensing as if about to cum, only to whine, tearing up as he couldn't get over that edge.  
  
Red snickered, turning away to grab another toy from the box as Blue moaned lowly, thrusting hard into Sans' mouth and cumming down his throat for what had to be the fourth time now. Sans still swallowed it down greedily, moaning at the burst of hot magic in his throat. Red listened as Blue panted softly, the gentle clack of bone on bone resuming as Blue began thrusting again while he dug through the toy box.  
  
After a few minutes, he dug out a thick vibrator with a built-in clit stimulator and grinned again. Perfect. Turning back, he watched as Blue fucked Sans' face for a moment, noting the tears in Sans' socket, but also how his eyelights were in the shape of hazy hearts. Perfect. They hadn't gone too far yet. Slowly, he pressed the head of the toy against Sans' soaked pussy, pausing to rub it up and down the cleft to coat the silicone in Sans' slick before pressing it to his entrance. Sans' cunt seemed eager for the stimulation as it almost sucked the toy in once Red had gotten the head inside.  
  
Red snickered again, hilting the toy in a motion that was probably far too quick, though Sans just moaned. Sans had literally no idea what was coming to him though, as Red took a moment to thrust it in and out before once again hilting it and holding it in place as he turned the vibrator on, setting it to a powerful pulse setting right off the bat. Sans screamed louder than he had all night, entire body seizing again and again as he swayed back and forth on the edge, unable to go over. When Red added a thrusting motion back in, Sans started making incoherent sounds around Blue's cock that was likely begging. Another shriek was wrenched from him as Blue restarted the vibrations of the magic conduits and it wasn't long before Sans smacked Blue's hips, trying to pull off Blue's cock to speak.  
  
At a nod from Red, Blue released Sans, who collapsed to the floor without Blue holding him steady. "fuck, please, it's too much, stars, let me cum, let me cum! please!" Sans practically howled.  
  
"...fuck. blue, come here," Red growled, deflating the toy in Sans' ass and tugging it out, tossing it to the side to be cleaned later. "you're gonna fuck him until he cums while i continue working him over with the toy," he said, tone sharp with barely suppressed lust.  
  
"What about you?" Blue asked, getting into place behind Sans while Red helped Sans shift until he was up right and desperately clinging to Blue's neck to keep himself that way.  
  
"won't last. he's gonna have his heat to fuel his stamina, and yer a fucking energizer bunny, but i'm only gonna be able to cum once, maybe twice. it'll be better if i join in properly once he's crested the peak of his heat," Red replied, though it was clear that he really just wanted to ravage Sans right then and there. Blue nodded, lining up with Sans' entrance before pushing in slowly. He was only half way in before Sans, who'd still been incoherently begging to be allowed to cum, arched against him, screaming as he came hard enough that he must have blacked out for a moment. Blue went to pull out as soon as Sans had relaxed enough for him to do so, but Red shook his head.  
  
"just stay like that. his heat isn't gonna abate that easily," Red murmured, and Blue nodded, unable to help himself as he started rocking in and out shallowly.  
  
Sans came back around with a weak moan, unable to do anything but ride it out as Blue's movements drew out the pleasure from his orgasm until everything was just one pleasurable burn. Eventually, though, Blue's gentle rocking was no longer enough as his heat forced him to rebound, despite already feeling worn out. "nn... please... more..." he whimpered, and moaned when Red began thrusting the vibrator in his soaked cunt again. That felt good, but Sans ached for something _more_. "please... red... fill me up... fuck me, oh stars, please," he moaned, leaning back against Blue and clinging even more desperately than before.  
  
The moment Red's will broke was more than obvious. His eyelights contracted to narrow slits as he growled, yanking the toy from Sans' cunt with one hand while he freed his cock with the other. His dick was fatter and longer than normal with pent-up lust, and Sans moaned at the sight of it, spreading his legs more to invite Red in. Red took that invite, one hand hiking up one of Sans' legs, the other lining his length up with Sans' entrance before pushing in, barely managing to hold himself back from hilting himself in one harsh thrust. Even like this, he didn't want to risk hurting Sans.  
  
Sans, however, keened long and loud at the sensation of both his holes being stuffed with huge dicks. It felt so good and satisfied some deep part of him. When neither of them moved right away, it was Sans' turn to growl. "move, dammit!"  
  
"...fuck, sweetheart, yer..." Red snarled back, then started moving, setting a rough, hard pace that had Sans' eyelights rolling in his skull as he sunk against Blue, who'd set a gentle rocking pace counterpoint to Red's roughness. The opposing sensations quickly pushed Sans closer and closer to the edge until he was cumming again with a sharp cry. Red did not stop or even slow even as Sans tightened impossibly around him, simply fucking Sans through it and beyond. For Sans, one orgasm seemed to melt into another until he was a panting, crying mess, jaw hanging open and tongue lolling, unable to do anything but moan and whimper at the continuous overstimulation.  
  
It seemed to take forever, but one last nearly painful orgasm tore through him before he felt like he wouldn't be able to take anymore. "please, stars... red, blue, inside me, i want to feel it," he keened softly. Red snarled out a curse, biting Sans' collar bone just hard enough to anchor himself as he hilted one last time, cumming deep inside Sans' magic. Likewise, Blue only managed a few more gentle thrusts before he was cumming as well. The sensations pushed Sans over the edge again and he let out a weak, broken moan before falling limp in the arms of his alternates.

\--------------------------------------------

Sans woke feeling satiated like he'd never been before, though his entire body felt like so much jello. He let out a small sound, attempting to shift, but his hips gave a tiny, painful twinge and he winced. "heh... yer awake... as i'm guessing ye've noticed, ya probably... shouldn't move around too much..." Red's voice came from the doorway, guilt lacing his words, and Sans silently looked over. "i might'a lost myself a bit and was too rough with ya..." he murmured. "blue's fetching some ointment right now that should sooth the ache, though. other than the uh... the pain, how are ya doin'? heat abated?"  
  
"yeah... thanks. pelvis aches and i feel kinda like jello shaped into bones, but... i feel good," Sans rasped, then blinked as he realized just how bad his voice sounded. Red flinched at that, coming into the room properly and fetching a glass of water that had been left on the night stand.  
  
"here, sweetheart. ya were screaming quite a lot. ya probably strained yer voice," Red said softly, helping Sans sit up enough to drink. The first sip of cold water made Sans realize just how thirsty he was, but Red didn't let him gulp the water like he wanted. Instead, he was given small mouthfuls at a time until the glass was empty. "there. how's that feel?"  
  
"mmm... better," Sans replied, his voice coming stronger that time. Red looked relieved. "seriously. thank you both. i wouldn't have gotten through that one on my own with how deep i was in my heat already..."  
  
Red's sockets narrowed at that. "speaking of... why _did_ ya forcefully suppress yer heat?" he asked, and Sans groaned.  
  
"i uh... my heats typically last nearly a week since i usually don't get help and deal with it on my own... i realized i was going into heat three days before the party, and instead of being smart and seeking a partner to deal with it faster, i just... suppressed it so i wouldn't disappoint paps by skipping the party..." Sans replied with an embarrassed flush.  
  
"...i thought ya were supposed ta be the smart one..." Red growled for the second time that day. He then sighed, shaking his head. "fuck, next time yer heat sets in right before an event like this, come to me or Blue fer help," he said softly, then leaned forward and kissed Sans on the forehead gently.


End file.
